Women can be a powerful force, capable of making smitten men do all sorts of things, including adjust the way they talk to more closely match a woman’s speech patterns.

Conversation partners aligning the way they speak is often thought to indicate affiliation between two people. Have a chat with someone who curses liberally, for example, and the likelihood is good that you’ll drop a swear word too. While matching linguistic styles is a documented phenomenon, what’s particularly interesting is that new research shows that higher levels of female fertility are linked to lower levels of linguistic matching from male conversation partners.

According to a study published last month in the journal PLoS ONE, researchers interpret this to mean that men are trying to distinguish themselves in the mating process by being unconventional. What’s more, they don’t seem to even realize they ‘re doing it.

Jacqueline Coyle, an adjunct professor of human factors and systems at Embry-Riddle Aeronautical University, followed 123 male undergraduate students who interacted with five female undergraduate students at various points throughout the women’s menstrual cycles. The women, whose menstrual cycles were tracked, weren’t relying on hormonal contraception.

In the study, a man and woman alternated describing a picture to one another. The woman used a script in order to help researchers more clearly see how men’s sentence structure correlated with women’s. Where a woman was in her monthly menstrual was also noted.

The closer to ovulation a woman was in her cycle, the less likely a man was to mimic her sentence structure. “This finding demonstrates that men may use creative or non-conforming language as a means of attracting a potential romantic partner,” says Coyle.

In another study, Coyle flip-flopped the approach and repeated the experiment using 47 female undergraduate students. Women behaved more conventionally: their fertility level did not appear to affect the degree to which they matched their conversation partner’s sentence structure. In other words, the effect seems specific to men.

The research adds to an already significant body of work showing the behavioral effects of female fertility on males. When Coyle was in graduate school at Florida State University, some of her colleagues were investigating how exposing men to the scent of an ovulating woman, for example, affects their perceptions, behavior and even their physiological responses. Coyle wondered whether language might also be influenced.

An argument could have been made for diametrically opposing results. After all, wouldn’t men want to match their conversation more closely to their desired woman’s in order to create feelings of similarity and hence intimacy? “We were very curious to see which way the results would go,” says Coyle. “Many people in the general population may not realize that the effects of a woman’s fertility level go well beyond chocolate cravings, moodiness, and one’s chances of conception.”